Compact photonic crystal multichannel drop filter for CWDM systems

Abstract

A novel photonic crystal channel drop filter (PCCDF) is proposed to drop four coarse wavelength division multiplexing (CWDM) channels at 1490 nm, 1510 nm, 1530 nm and 1550 nm. A special coupled dual-loop design was used for multichannel forward/backward dropping for the first time. Due to the reduced number of the dropping resonators with this design, the proposed multichannel PCCDF has a very compact size (338 μ m2). High transmission efficiencies at the four ITU wavelengths (87.87%, 93.99%, 85.40% and 84.24%) can be obtained simultaneously. Furthermore, the same dimension parameters (lattice constant and rod radius) of the dual-loop resonators are helpful for easy fabrication. The proposed device could be used in future photonic integrated circuit-based CWDM communication systems.